The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

An Appeal Panel hearing was held on February 11, 2004, at the request of a union representative, acting on behalf of the claimant. The Panel discussed this appeal on several occasions, the last one being August 12, 2004.

Issue

Whether or not the bilateral cubital tunnel syndrome arose out of and in the course of the worker's employment.

Decision

That the bilateral cubital tunnel syndrome arose out of and in the course of the worker's employment.

Decision: Unanimous

Background

On April 27, 2001, the claimant injured his right wrist after cutting meat with a wizard knife during the course of his employment as a production worker. Examination by a chiropractor on June 18, 2001 diagnosed the claimant with right carpal tunnel syndrome (CTS). The claimant was considered capable of performing modified duties and was provided with a wrist support.

In a letter dated August 10, 2001, the accident employer noted that the claimant had been transferred to a new position working on the butt line two weeks before the report of injury. He was placed on light duties on April 27, 2001 and when it was determined that he was physically unable to perform the duties of the new position, he was returned to his old job. The employer noted that the claimant's pain resulted from a lack of conditioning to the new job which required strong gripping and the use of a vibratory wizard knife.

The claimant underwent nerve conduction studies on August 20, 2001. The results revealed minimal bilateral carpal tunnel syndrome and severe focal bilateral ulnar neuropathy of the ulnar grooves.

On September 27, 2001, the treating plastic surgeon recommended that the claimant undergo decompression of the right cubital and carpal tunnel syndrome.

On October 2, 2001, an adjudicator with the Workers Compensation Board (WCB) spoke with the claimant to gather additional information about his work history and duties that he performed over the years with the accident employer.

The case was reviewed by a WCB medical advisor on October 15, 2001. The advisor was of the opinion that the claimant's carpal tunnel syndrome might be related on the basis of an aggravation of a pre-existing condition. He thought the cubital tunnel findings were not work related although no comprehensive rationale or basis for that opinion was provided.

On October 16, 2001, the claimant was advised that the WCB was accepting responsibility for his right CTS condition but would not accept responsibility for his bilateral elbow difficulties.

In a medical summary dated June 4, 2002, a WCB Medical Advisor provided an initial summary of the claimant's work history. He noted that by December 1997, the claimant was unable to work with a wizard knife due to cramping on the hand and difficulty with hand opening.

On November 7, 2002, a union representative, acting on behalf of the claimant, wrote to the WCB concerning several issues, one of which was the decision of the WCB to deny responsibility for the claimant's bilateral cubital tunnel syndrome. The union representative believed that there was a relationship between the claimant's elbow condition and the work duties that he performed.

In support of this contention, the union representative relied on a report from the claimant's treating plastic surgeon dated October 10, 2002 and a report by the attending physician dated October 27, 2002. In his letter, the claimant's attending physician provided his view that "there did not appear to be any precipitating cause for these symptoms other than his use of certain equipment in the course of his work duties (especially vibrating tools). In the absence of any other feasible explanation, it is my opinion that [the claimant's] bilateral ulnar neuropathy is work related."

Following consultation with the healthcare branch of the WCB on November 20, 2002, the case manager wrote to the union representative on December 6, 2002. The following is an excerpt from that letter:

"Information on file supports the fact that [the claimant's] condition is pre-existing and not caused or related to his job duties. Clarification was sought regarding likely causes of cubital tunnel syndrome. The opinion offered is that the primary cause of this condition is trauma direct to the elbow by night time sleep positioning, particularly in someone predisposed with minimal tissue protection of the nerve or with a shallow groove. A tight cubital tunnel or compression bands also represent pre-dispositions to cubital tunnel syndrome. The list of aggravating factors noted by [the treating plastic surgeon] are accepted for carpal tunnel syndrome but do not apply to cubital tunnel syndrome."

Based on the above, the WCB was unable to accept responsibility for the claimant's bilateral condition as being related to either his April 27, 2001 work injury or to his job duties. It was determined that his bilateral elbow condition was not caused or enhanced by the accident or his job duties. On December 11, 2002, the union representative appealed this decision to Review Office.

In a decision dated February 14, 2003, Review Office took the position that the claimant's bilateral cubital tunnel syndrome did not arise out of and in the course of his employment. Review Office was concerned that the claimant's arm conditions were bilateral in both the CTS and cubital tunnel scenario. "The reason for this concern is the fact that the claimant is right handed and thus it is the right hand accepting the vast majority of any stressors being applied during the course of the employment. This would not explain the claimant's left side findings, and thus gives credibility to a philosophy that there is a non-work related component in this scenario."

Review Office noted that the claimant had been off work for over nine months and yet he still had numerous physical complaints and appeared to be symptomatic on both the right and left side of his upper limbs. This, to Review Office, lent credibility to a non-work related influence on the claimant's symptomatology.

In a letter dated May 5, 2003, the claimant's plastic and reconstructive surgeon suggested that while there were difficulties in determining if the claimant's left elbow problem was work related "if he has a history of his symptoms being exacerbated by his workplace activities, then my opinion would be that it would be a compensable problem."

On September 19, 2003, a physician from the Occupational Health Centre provided a thorough summary of the claimant's work history with the employer. His summary was confirmed by the claimant at the oral hearing. Although the exact volume and intensity of the claimant's work experience may not be amenable to precise calculation, the panel is satisfied on a balance of probabilities that the following summary accurately reflects the claimant's work experience. For the purposes of convenience, the transcript pages on which various references appear are also cited.

By July 1993, the claimant was working on the belly line trimming and packing pork bellies. During the course of an 8 hour shift many hundreds of bellies weighing in excess of 10 pounds were trimmed (Transcript, page 13) At this time, the claimant used a regular butcher knife in his dominant right hand. As noted during the oral hearing, the claimant repeatedly used his left hand to flip the bellies while he worked on them. The flipping of the bellies involved both a right to left and a left to right motion of the left elbow. (Transcript, page 15)

The occupational health physician went on to note that in April 1997, the job changed. Rather than employing a butcher knife, the claimant began to use a wizard knife with a vibrating electric powered blade. As noted during the oral hearing, the vibrations became especially pronounced when the blade was dull (Transcript, page 31) .

Given the new technology, production doubled and the claimant began to experience difficulties with his hands (Transcript, page 24 -26). After using the wizard knife for two hours before a break, the claimant lost power to open his right fingers and hand (Transcript, page 32).

As noted during the oral hearing, the claimant continued to use his left hand to flip the bellies while he worked. Although he did suffer numbness, the symptoms were less pronounced on his left hand (Transcript, p. 36)

After the claimant brought his complaint to his supervisor's attention, he was switched to a different position not involving a wizard knife. With the switch in duties, the claimant's right hand and forearms complaints slowly resolved.

The occupational health physician went on to note that in April 2001, the claimant accepted a new job on the picnic line. The first month went well until the claimant was assigned an additional task of trimming bellies with a wizard knife. "Within ten minutes back on the wizard knife, (the claimant's) wrist and fingers locked up with stiffness; he was given temporary restrictions from using the vibrating knife. However, by mid-May deboning on the picnic line, he developed burning pain on the medial aspect of his right elbow associated with gripping and handling the knife."

Based upon his extensive review of the claimant's work history, the occupational health physician concluded that "the onset of his right arm problems was directly related to highly repetitive use of the arm as a butcher, combined with using the vibrating wizard knife which heightened symptoms of pain, weakness and hand numbness." He also noted that "there is little, if any contributions of non-occupational factors contributing to developing this condition."

In terms of the claimant's bilateral elbow condition, the occupational health physician's conclusion was that "the years of working as a butcher, gripping his cutting knife and wizard knife in the right hand likely contributed significantly to his development of right elbow pain, whereas the left side may be due to gripping and throwing the meat product on the assembly line."

On October 31, 2003, the union representative appealed Review Office's decision.

On February 11, 2004, an oral hearing took place at the Appeal Commission at which time it was agreed that both the union representative and the employer's advocate would be providing the Panel with literature research on the topic of cubital tunnel syndrome. Additionally, the Appeal Panel asked the employer's advocate to provide a "Physical Demands Analysis" of all the job functions that the claimant performed during his career with the accident employer.

Both parties provided additional literature on the subject of cubital tunnel syndrome. In addition, the Panel was provided with an Appeal Panel decision dated June 25, 2001 which had rejected the suggestion that a right ulnar nerve problem was the consequence of a workplace injury.

In a letter dated March 9, 2004, the employer's representative indicated that the company was not in a position to provide a "Physical Demands Analysis" of all the job functions that the claimant performed during his career with the accident employer because only preliminary work had been done in defining the ergonomic requirements of each position. The company was also not in a position to identify the periods in which the claimant worked in different departments due an absence of detailed records along with personnel change.

On April 8, 2004, the Panel met again to discuss the case and decided to arrange for a work site visit to view the claimant's previous job activities with respect to the use of a wizard knife, circle knife and packaging jobs.

During the course of the work site visit, the Panel had the opportunity to view the work site as it currently exists. The Panel notes that the work site had undergone a number of changes from the time that the claimant worked there. For example, the current auger set-up is different from the one used by the claimant when he first started working in that area. More significantly, the type of wizard knife currently used at the work site is different from the type the claimant used. However, the Panel did have an opportunity to hold and assess the degree of vibration associated with an older wizard knife similar to the one originally used in the workplace by claimant. The Panel appreciates the courtesy and cooperation of the employer in facilitating the work site visit.

In a letter dated May 13, 2004, the employer's representative argued that "the wizard knife is light with very little vibration." In her submission, there was "no heavy, vibrating equipment used at [employer] that could account for the ulnar nerve problems and certainly not affecting both the dominant and non-dominant hands." She also suggested that the claimant's sleep patterns might offer an alternative explanation for his bilateral cubital tunnel syndrome.

Following the work site visit which took place on May 3, 2004, the Panel requested and obtained additional information from the claimant's treating plastic and reconstructive surgeon with respect to the claimant's March 6, 2003 left hand surgery.

In a letter dated May 31, 2004, the claimant's treating plastic and reconstructive surgeon noted that "at the time of surgery a thick fibrous band was identified that was felt to be the point of constriction. It was located just distal to the cubital tunnel."

In his view, "the etiology of this thick fibrous band is likely related to the presence of normal fascial tissue that has become thickened over time from either chronic repetitive injury or perhaps due to an isolated injury. It is not a structure that is normally found in this region under normal circumstances. It is possible that if [the claimant's] occupation involved repetitive activities with his elbows that these activities could have created this thickening of this fibrous tissue over time or certainly would have enhanced it."

This information was shared with the interested parties. On August 12, 2004, the Panel met to render its final decision with respect to the issue under appeal.

Reasons

Overview

In reaching its decision, the Panel considered the entirety of the record including the medical opinions and literature, the oral hearing and the work place visit. Based upon its review of the record, the Panel finds on a balance of probabilities that the claimant's bilateral cubital tunnel syndrome arose out of and in the course of his employment.

Neuropathy

The ulnar nerve is responsible for muscle function in the hand and sensation along the ring and small finger. Neuropathy is described as pain and decreased function of the ulnar nerve when the nerve becomes constricted (entrapped) or compressed along its route from the neck to the hand. The nerve must travel through a tunnel at the elbow and canal in the wrist, both potential sites for entrapment and irritation.

The nerve can become constricted (entrapped) at the elbow or wrist from swelling caused by direct pressure over the nerve tunnel/canal. In the elbow, this tunnel is along the back and inside of the elbow (cubital tunnel). The nerve may also slide out of this groove or tunnel when the elbow is bent (flexed) causing irritation and swelling (neuritis, neuropathy). Common causes for ulnar entrapment at the elbow include activities that require repeated bending of the elbow. These include driving, sleeping, keyboarding, weightlifting and pitching a baseball. (Neuropathy of the Ulnar Nerve)

Is the Injury Related to the Workplace?

In the case before the Panel, there is no disputing that the claimant suffers from bilateral cubital tunnel syndrome. What is at issue is whether the claimant's condition arose out of and in the course of his workplace.

As a starting point for its analysis, the Panel would note that a number of non-work place risk factors related to cubital tunnel syndrome have been eliminated. For example in his letter dated September 19, 2003, the occupational health physician observed that risk factors such as diabetes, thyroid and alcohol problems had been queried and discounted. In his view, there was little "if any, contributions of non-occupational factors contributing to developing this condition." To similar effect, the attending physician in his letter dated October 27, 2002 concluded that "there did not appear to be any precipitating cause for these symptoms other than his use of certain equipment in the course of his work duties."

Given the elimination of a number of non work related risk factors, the central debate in determining the merits of the claim turns on two competing theories of causation. The evidence of the WCB Medical Advisor suggests that the claimant's injuries were caused by "direct trauma to the elbow by night time sleeping position." From this perspective, given that the claimant was right hand dominant what else would explain the bilateral condition?

In contrast, the occupational health physician, the attending physician and the plastic and reconstructive surgeon suggest that the injuries arose out of and in the course of employment. In particular, all three physicians suggest that the right elbow injury is attributed to the powerful vibrations of the wizard knife while the occupational health physician and the plastic and reconstructive surgeon were of the view that the left elbow injuries may have been or were related to repetitive motions on the assembly line.

In considering the extensive evidence on file, the Panel is persuaded that the better view is that the claimant's injuries are work place related. While there is some opinion which might be taken to suggest that the claimant's injuries could be related to his sleeping patterns, the evidentiary source for the WCB Medical advisor's opinion is not well documented or analytically related to the claimant's personal circumstances. The limited oral evidence from the claimant as to the nature of his sleeping patterns is also ambiguous and does not, in the Panel's view, provide a sufficient foundation for a determination that the injuries are related to sleeping patterns. By contrast, there is an extensive and well documented body of evidence which supports the opinion that the injury is work place related.

In making its determination, the Panel places heavy weight on the claimant's own evidence provided at the oral hearing as well as the opinions of the occupational health specialist dated September 23, 2003 and of the plastic and reconstructive surgeon dated May 31, 2004.

Based upon this evidence, the Panel finds on a balance of probabilities that the onset of the claimant's right arm problem was directly related to highly repetitive flexion of his right arm as a butcher, combined with the use of the vibrating wizard knife. While the employer's representative suggests that the wizard knife does not vibrate heavily, the Panel accepts the claimant's contention that it does vibrate heavily particularly when dull.

In making this conclusion, the Panel is supported by its own experience with the older wizard knife during the course of its plant tour.

The Panel also notes that the onset of the claimant's concerns both in 2001 and in 1997 are closely related in time to his usage of the wizard knife. While a change in duties in 1998 served to relieve the claimant's distress for a time, the problem reoccurred once the claimant resumed using a wizard knife in 2001.

The Panel notes that the opinion of the occupation health physician as to the etiology of the bilateral cubital tunnel syndrome was buttressed by the most thorough review of the claimant's work place experience which appears on the record. This review is corroborated by other pieces of evidence including the WCB Medical Advisor's summary dated June 4, 2002, the claimant's oral evidence and the plant tour in 2004.

Turning to the injury to the left elbow, the Panel accepts the claimant's oral evidence as to the nature of the usage of his left elbow in the workplace over time. It notes that much of his work involved repetitive flexion and pronation of his left elbow.

The Panel observes that the most recent information on the record stems from the May 31, 2004 letter of the plastic and reconstructive surgeon who suggested that "if [the claimant's] occupation involved repetitive activities with his elbows . . . these activities could have created this thickening of this fibrous tissue over time or certainly would have enhanced it." His views are supported by the occupational health physician who pointed to the assembly line as a possible cause of the claimant's left elbow injury.

The Panel finds on a balance of probabilities that the cubital tunnel syndrome in his left elbow was either caused by or enhanced by his employment.

In terms of the previous decision of an Appeal Panel date June 25, 2001, the Panel does not find it to be of material assistance given the different fact situation and evidentiary record. The precedential value of that decision, like the decision in this appeal, can be restricted to its specific facts.

For the reasons stated above, the Panel finds that the claimant's bilateral cubital tunnel syndrome arose out of and in the course of his employment. The appeal is allowed.

Before concluding, the Panel wishes to thank the claimant and the claimant's representative as well as the employer and the employer's representatives for their diligent presentations which greatly assisted its deliberations. The Panel also wishes to note that the current workplace appears to be a materially different place in a number of respects from the workplace in which the claimant suffered his injuries.

Panel Members

B. Williams, Presiding Officer
A. Finkel, Commissioner
M. Day, Commissioner

Recording Secretary, B. Miller

B. Williams - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 29th day of September, 2004